Harmonica



FIG. 1 is a top front perspective view of a harmonica showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a rear plan view thereof; and,

FIG. 6 is a left side view thereof, the right side view being a mirror image. 

The ornamental design for a harmonica, as shown and described. 